Footwear with retractable spikes

ABSTRACT

An apparatus for selectively extending and retracting spikes includes spike actuating assemblies mounted to, and cooperating between, a first plate and a first slider frame, and a second plate and a second slider frame, pivotally mounted to the first plate and first slider frame respectively. Each spike actuating assembly contains a spike. The first slider frame is translatable to actuate the spike actuating assemblies to thereby extend and retract the spikes from the spike actuating assemblies. A cyclically alternating positioner is mounted on the first plate for moving the first and second slider frames relative to the first and second plates. The positioner has only a single actuating button adjacent the heel. Depressing the actuating button a first time causes the positioner to move the slider frames to extend the spikes. Depressing the actuating button a second time causes the positioner to move the slider frames to retract the spikes.

FIELD OF THE INVENTION

The present invention relates to footwear in general and to a method and apparatus for providing footwear with selectively extendable spikes in particular.

BACKGROUND OF THE INVENTION

Traction is necessary for proper performance in many endeavors including those involving sports and recreation, professions and trades including fire fighting and policing, in the military and in particular infantry, to name just a few. For example, in the sport of golf, proper traction is required during full swing shots such as the tee shot and many fairway shots. Due to the grass covered surfaces on which golf is played, however, proper traction may be difficult. It is well known that the addition of spikes to the bottom of footwear for golf shoes helps to provide the necessary traction on such a surface. Such spikes were traditionally made of sharpened elongate metal projections.

Traditional metal spikes, however, suffered from the disadvantage of being damaging to some surfaces. In particular, the putting greens surfaces which have a significantly shorter grass length have been found to be damaged by metal spikes. Such metal spikes have been known to cause significant damage to putting greens by leaving holes and ridges in the ground as well as damaging the more delicate putting green grasses.

One solution to the above disadvantages of metal spikes has been to replace the traditional metal spikes with a spike insert comprising a plurality of plastic or rubber protrusions which are also known as the “soft spike”. Soft spikes have resulted in less damage to the putting greens surfaces. Accordingly, many golf courses have enacted rules prohibiting traditional metal spikes in favor of soft spikes. However, soft spikes have also reduced the traction provided to the golfer during full swing shots such as the tee shot. Therefore, while most recreational golfers now use soft spikes, many professional players continue to use metal spikes. The use of metal spikes for professional golf tournaments results in a significant amount of damage to the putting greens which is both costly to repair as well as obstructive to the play of later players.

Soft spikes have also not completely eliminated the damage occurring to golf course greens. As developers of soft spikes have attempted to increase the traction provided by soft spikes, the amount of damage these spikes inflicts on putting greens increases. In particular, it is known that metal spikes and newer designs of soft spikes results in damage to the structure of the grass making these grasses more susceptible to disease and other difficulties. Putting greens therefore require more fungicides, pesticides and water to ameliorate the damage caused to the grass from metal and soft spikes.

In these and other uses such as in the military, for use outdoors, or in sports other than golfing, or for other recreational or trades or professional uses where selectively actuable traction offered by selectively extendible and retractable spikes is advantageous, it is also advantageous and an object of the present invention to provide a structure substantially or more advantageously even entirely enclosed from the outside elements in a sole which is rugged and yet flexes with at least the toe portion of the foot of the wearer.

In the prior art attempts have been made to provide shoes with selectively extendable and retractable spikes. Examples of such shoes may be found in U.S. Pat. Nos. 4,821,434 to Chein, 6,058,627 to Violate et al., 5,299,369 to Goldman, 6,256,907 to Jordan et al, and 4,375,729 to Buchanen, III, and in Canadian patent application no. 2,510,291 filed May 27, 2005 by Jones. However, such devices have not been suitable as for example in some there are separated controls to extend or retract the spikes. Several of these controls are located in the toe of the sole where they may cause tripping while climbing or in inclined terrain or be prone to actuation for example during the follow-through of a golf swing, etcetera. Other designs in the prior art are inferior in that relatively large pieces of actuating structure are exposed outwardly of the sole making damage to the structure or the intrusion of water, dirt, snow, etcetera more likely.

Other attempts have required the user to activate the extension or retraction of the spikes from the sole of the shoe by manipulating a tab lever, screw or other device on the sole of the shoe itself. Examples of such devices maybe found at U.S. Pat. Nos. 5,836,092 to Yarnell, 5,497,565 to Balgin, 6,389,714 to Mack, 5,956,870 to Grossman et al., 6,256,907 to Jordan et al., 5,732,482 to Remington et al., 5,870,838 to Khayat and 5,269,080 to Davis. Such devices have not been acceptable due to the need to bend down to extend or retract the spikes which may be difficult for some users and time consuming.

SUMMARY OF THE INVENTION

The present invention is an apparatus for selectively extending and retracting spikes from the sole of a footwear article, where the sole has a heel section, a center under-the-arch of the foot section (herein a “center” section), a ball-of-the-foot section (herein a “ball” section), and toe section extending consecutively in a longitudinal direction along the sole. A plurality of spike apertures are formed through the heel, ball and toe sections. The apparatus includes spike actuating assemblies mounted to, and cooperating between a first plate and a first slider frame, and a second plate and a second slider frame. Each spike actuating assembly contains a spike which is locatable within a corresponding one of the spike apertures in the sole.

The first plate has heel, center and ball portions sized to extend over so as to cover respectively the heel, center and ball sections of the sole when the first plate is mounted on the sole. The first slider frame is elongate and longitudinally translatable mounted flush on the first plate. The first slider frame has heel, center and ball sub-frames covering respectively the heel, center and ball portions of the first plate. The first slider frame is translatable between first and second positions. The first slider frame is operable to actuate the spike actuating assemblies to thereby extend the spikes from the spike actuating assemblies at the first position and to retract the spikes at the second position.

A cyclically alternating positioner is mounted on the first plate for moving the first slider frame between the first and second positions. The positioner has only a single actuating button adjacent the heel portion. Depressing the actuating button a first time causes the positioner to move the first slider frame to the first position. Depressing the actuating button a second time causes the positioner to move the first slider frame to the second position.

The second plate is adjacent a front end of the ball portion of the first plate so as to cover the toe section of the sole when the first and second plates are mounted on the sole. The second slider frame is slidably mounted flush on the second plate. The second slider frame pivotally is mounted to a front end of the ball sub-frame of the first slider frame. At least one spike actuating assembly is mounted on the second plate. When the first slider frame is moved between the first and second positions, the second slider frame is correspondingly simultaneously moved relative to the second plate and correspondingly actuates the spike actuating assembly on the second plate to simultaneously extend and retract a corresponding the spike therefrom.

Each spike actuating assembly further comprises a rigid housing mounted to the first plate and slidably encases a corresponding the spike. In one preferred embodiment a knee-lever linkage is pivotally mounted at a first end thereof to the rigid housing and at an opposite second end to the first slider frame. The knee-lever linkage includes at least an upper link and a lower link pivotally mounted to one another at a mid-pivot between the first and second ends of the knee-lever linkage. The mid-pivot is connected to the corresponding spike. When the first slider frame is in the first position so as to extend the corresponding spike the upper and lower links are substantially linearly aligned and collectively upwardly inclined so as to transfer a substantial vector component of an upward force acting on the corresponding spike to the rigid housing via the mid-pivot and the linearity of the substantially linearly aligned upper and lower links.

In one preferred embodiment the center portion of the first plate is waisted when viewed in planform relative to a width of the heel and ball portions. The center sub-frame of the first slider frame is correspondingly waisted so as to substantially conform in width when overlaid onto the center portion.

The positioner may in one embodiment include a cyclical actuator mounted both on the center portion of the first plate and the center sub-frame of the first slider frame so as to cooperate therebetween to drive the first slider frame between the first and second positions relative to the first plate. In this embodiment a drive member extends between the button and the cyclical actuator.

Advantageously the spike actuating assemblies are mounted on the first plate in spaced apart array so as to provide a longitudinally extending unobstructed center corridor along the first plate extending substantially the entire length of the first plate. The array is also longitudinally spaced to provide longitudinal spacing between the plurality of spike actuating assemblies. The first slider frame includes a center back-bone frame extending substantially completely along the heel, center and ball sub-frames. The back-bone fame freely slides along the center corridor of the first plate. The first slider frame includes laterally extending arms from the center back-bone frame extending cooperating with the of spike actuating assemblies so as to actuate the spikes.

The laterally extending arms may advantageously further include longitudinally extending arms at the distal ends of the laterally extending arms in a T-shape for example, so as to define substantially U-shaped brackets around each spike actuating assembly. The U-shaped brackets drive each spike actuating assembly simultaneously from opposite sides thereof.

The first plate may further include guide members cooperating with the first slider frame to constrain sliding translation of the first slider frame between the first and second positions, and to constrain the translation to flush translation substantially flush along the first plate. In one embodiment the flush translation is without any vertical translation of the first slider frame relative to the first plate.

The actuating button may comprise a plunger button acting against a return biasing spring. The plunger button may cantilevered from a heel portion of the sole in a substantially horizontal plane. A portion of the sole covers the actuating button, or the actuating button maybe contained within the sole. The positioner is cyclically actuated by single consecutive pushes of the button applied to rear of the sole against a return biasing force of a single resilient biasing spring. The spring may act against and between the first plate and the button. The spring may be a helically coiled spring. A rod may extend from the button along the heel portion to the center portion of the first plate. The rod may be journalled through the helically coiled spring, and may be substantially parallel to the first plate and substantially longitudinally aligned.

In a preferred embodiment a third link in the knee-lever linkage is pivotally connected between the mid-pivot and an upper end of the corresponding spike. Advantageously, the upper link is mounted to the housing at an upper end of the housing, and the lower link is mounted to the first slider frame. In one embodiment the housing is a spike guide which defines a substantially vertical silo for a spike to slide vertically therein as the mid-pivot is lowered or elevated upon translation of the first slider frame between the first and second positions respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention wherein similar characters of reference denote corresponding parts in each view,

FIG. 1 is in front perspective view, a sole containing the spike actuating mechanism according to the present invention.

FIG. 2 is a bottom perspective view of the sole of FIG. 1.

FIG. 3 is, in front perspective view the spike actuating mechanism of FIG. 1 mounted to the wider-sole.

FIG. 4 is, in front perspective view, the shifter frame of FIG. 3.

FIG. 5 is, in bottom perspective view, the shifter frame of FIG. 4 showing the pins and pin holder of the push button actuating mechanism mounted thereto.

FIG. 6 is, in rear perspective view, the spike actuating mechanism of FIG. 3 with the under-sole, spike gaskets, shifter frame, and actuating rod removed.

FIG. 7 is the view of FIG. 6 with the shifter frame and leaf spring shown and with the mounting plate removed.

FIG. 8 is the combined views of FIGS. 6 and 7 with the shifter frame mounted overlaying the mounting plate.

FIG. 9 is, in enlarged perspective view, one of the knee-link assemblies and its corresponding spike taken from FIG. 7.

FIG. 10 is, in side elevation view, an enlarged portion of the spike actuating mechanism of FIG. 6.

FIG. 11 is, in bottom view, the spike actuating mechanism of FIG. 6.

FIG. 12 is, in plan view, the spike actuating mechanism of FIG. 11.

FIG. 13 is, in plan view, the spike actuating mechanism of FIG. 8.

FIG. 14 is, in plan view, an enlarged view of the front end of the spike actuating mechanism of FIG. 13.

FIG. 15 is, in perspective view, the spike actuating mechanism of FIG. 14 with the shifter frame removed.

FIG. 16 is, in side elevation view, the spike actuating mechanism of FIG. 8.

FIG. 17 is, in enlarged perspective view, the heel portion of the spike actuating mechanism of FIG. 6 wherein two outermost knee-links have been removed from one spike guide and wherein the single outermost knee-link has been removed from another of the spike guides to illustrate in more detail the arrangement of the three knee-links on either side of each spike guide in the spike actuating mechanism according to the present invention.

FIG. 18 is in enlarged perspective view the heel portion of the spike actuating mechanism of FIG. 3.

FIG. 19 is, in perspective view, an enlarged center portion of the spike actuating mechanism of FIG. 6.

FIG. 20 is a further enlarged view of the push button actuator as illustrated in FIG. 19 with the pin holder removed.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Sole 10 provides a resilient housing for example standing approximately between one half and three quarters of an inch high to define by a perimeter wall 10 a and enclosed internal cavity 12 in which is mounted the spike actuation assembly according to the present invention.

The spike actuation assembly includes a mounting plate 14 on which are formed or mounted substantially vertically up-standing spike guides 16. In the illustrated embodiment which is not intended to be limiting, four spike guides 16 are provided on the heel portion 14 a, four spike guides 16 on ball portion 14 b, and two spike guides 16 on separate toe mounting plate 18. A shifter frame 20 is mounted overlaid onto mounting plate 14 so as to overlay sub frame 20 a onto heel portion 14 a and sub frame 20 b onto ball portion 14 b. Sub-frames 20 a and 20 b are interconnected by a relatively narrower or waisted center sub-frame 20 c which overlays onto a corresponding waisted portion 14 c of mounting plate 14.

Sub-frames 20 a and 20 b each include oppositely disposed t-frames 22 extended cantilevered on members 22 a from center sub-frame extensions 20 d and 20 e extending into sub-frames 20 a and 20 b respectively from the corresponding ends of center sub-frame 20 c. Gussets 22 b lend rigidity to members 22 a at the intersections of members 22 a with sub-frames 20 e and 20 d, and also lend rigidity to t-frames 22.

Pins 22 c are mounted onto the opposite ends of the cross bars of t-frames 22 and are laterally aligned, inwardly disposed in opposed facing relation to the pins 22 c mounted on the opposite t-frame 22. In total four t-frames 22 are mounted to the center section of shifter frame 20, disposed so as to define a generally rectangular frame having a narrow waisted section in the middle. The t-frames 22 in conjunction with the sub-frames 20 d and 20 e form generally U-shaped structures which support pins 22 c on a first side of the U-shape and pins 24 on the opposite side of the U-shape, mounted so as to extend laterally of sub-frames 20 d and 20 e. Pins 24 align in opposed facing relation with the corresponding pins 22 c on the corresponding t-frame 22.

Pins 22 c are mounted to one end of exterior knee-links 26. The opposite ends of exterior knee-links 26 are pinned by means of pins 28 a to the common ends of knee-links 28 and knee-links 30.

The pins 24 and the opposite ends of shaft 32 are pivotally mounted to one end of interior knee-links 34. Interior knee-links 34 are pinned by pins 28 b to the common ends of knee-links 28 and knee-links 30. The opposite ends of knee-links 28, opposite from pins 28 b are pivotally mounted to pins 28 a rigidly mounted to and extending laterally from spike guides 16. The opposite ends of knee-links 30, opposite from pins 28 b are pivotally mounted to the upper ends of spikes 36 by pins 30 a.

Spikes 36 are slideably mounted within vertically elongate generally cylindrical hollow bores 16 b formed in spike guides 16. Oppositely laterally disposed vertical slots 16 c are formed in the side-walls of cylindrical bores 16 b. The ends of knee-links 30 opposite pins 28 b are pivotally mounted to spikes 36 by pins 30 a extending from knee-links 30 through slots 16 c.

Longitudinal translation of shifter frame 20 in direction A pulls exterior knee-links 26 and interior knee-links 34 simultaneously in direction B thereby driving knee-links 30 in direction C as constrained by slots 16 b. This drives spikes 36 downwardly in direction D into their fully extended position. Once in their fully extended position, spikes 36 are held in place by the tension provided by shift frame 20 on knee-links 26 and 34, transmitted to knee-links 30 by pins 28 b, and transmitted to spikes 36 by pins 30 a. It is important to note that most of the reactive force resisting the retraction of spikes 36 in direction D′ comes not from an upward pressure applied to shifter frame 20 via the pins and links but rather as a result of an upward force acting on spike guides 16 by the transfer of a reactive force along substantially that of force vector line E shown in dotted line. As indicated by force vector line E, links 28 and 30 are substantially co-linear when the spikes are fully extended. Thus most of the reactive force resisting the pushing of spikes 36 back up bores 16 b when a user wearing footwear containing soles 10 according to the present invention steps down onto firm or solid ground, is transferred between spikes 36 and spike guides 16 by pins 30 a, substantially along the longitudinal axis of knee-links 30, and via pins 28 b to be transferred substantially along the longitudinal axis of knee-links 28, and then via pins 28 a to spike guides 16. Thus, rather than bearing the brunt of the reactive force, shifter frame 20 primarily maintains tension on knee-links 26 and 34 in direction A and thereby tension on the junction between links 28 and 30.

When it is desired to retract spikes 36 upwardly so as to occupy bores 16 b, the push button release mechanism 48 as better described below is actuated by pressing button 38 in direction F and then releasing button 38. This releases rod 40 so that rod 40 may translate in direction G urged by the resilient expansion of helical coil spring 42 mounted between button 38 and end plate 44. End plate 44 is rigidly mounted to so as to vertically extend from the end of heel portion 14 a of mounting plate 14. Button 38 is rigidly mounted on the rear most end of rod 40. Rod 40 extends longitudinally along and over heel portion 14 a and is rigidly mounted to shifter frame 20 at its end opposite to button 38, and in particular to sub-frame 20 d by means of a pair of brackets 46.

Translation of rod 40 in direction G by the action of spring 42 urging button 38 in a direction opposite to direction F, translates shifter frame 20 in direction A′, that is, opposite to direction A. As shifter frame 20 translates in direction A′, t-frames 22 and in particular pins 22 c drive knee-links 26 and 34 upwardly in a direction opposite to direction B thereby drawing knee-links 30 upwardly in a direction opposite to direction C guided upwardly along slots 16 b, to thereby retract spikes 36 upwardly in direction D′, that is, opposite to direction D. Shifter frame 20 and therefore spikes 36 are held in that position by the resilient biasing of spring 42 acting on rod 40.

When it is desired to extend spikes 36 from their retracted position, button 38 is again pushed in direction F and released. Pushing button 38 collapses spring 42, driving rod 40 in a direction opposite to direction G, and thereby driving shifter frame 20 in direction A so as to operate the knee-links in the manner described above. In a preferred embodiment it is understood that the distal end of button 38 would only protrude from the heel end of sole wall 10 a sufficiently to be operable by a rearward kicking action of sole 10, the translation distance of rod 40 being kept to the minimum necessary to actuate the push button controller 48 as better described below. In one preferred embodiment, a resilient skin or cover or extension or compartment of sole wall 10 a extends around so as to completely cover button 38 to thereby minimize the likelihood of intrusion of water, dirt or other material into the cavity 12 within sole 10. It is understood that, although not shown, seals (not shown) such as known in the art would be employed around button 38 where the button extends from the sole (if not fully contained within the sole) and around spikes 36 where they extend through rigid spike gaskets 50. Spike gaskets 50 are rigidly mounted into the underside of under-soles 10 b. In one embodiment, a flexible fore-sole 10 c is a affixed to the front edge of under sole 10 b to allow for the upward flexing of the toe-end of sole 10 as toe mounting plate 18 pivots upwardly during use as better described below.

Translation of shifter frame 20 in direction A also shifts toe shifter frame 52 forwardly in a longitudinal direction forward of ball portion 14 b of mounting plate 14 via shaft 32 and toe shifter links 54. Toe shifter links 54 are pivotally mounted at one end to shaft 32 and pivotally mounted at their opposite ends to toe shifter frame 52 so as to directly transmit longitudinal translation of shifter frame 20 to toe shifter frame 52 while allowing rotation of toe shifter frame 22 and toe mounting plate 18 in direction H out of a plane parallel to that of mounting plate 14. Rotation of toe shifter frame 52 and toe mounting plate 18 in direction H about both axis of rotation 1 and shaft 32 provides for flexing of the toe portion of sole 10 for example while a user is walking while wearing footwear containing soles 10, without interfering with the actuation of a pair of spikes 36 mounted in a corresponding pair of spike guides 16 on toe mounting plate 18.

The operation of the spike actuators cooperating on toe mounting plate 18 with toe shifter frame 52 are as described above with respect to the spike actuators on mounting plate 14. Thus toe shifter frame 52 is W-shaped so as to define a pair side by side U-shaped collars and corresponding corner reinforcing gussets. In particular, the arms 52 a and base legs 52 b of toe shifter frame 52 are reinforced corner gussets 52 c and rigidly support at the distal ends of arms 52 a pins 22 c. As before, pins 22 c are pivotally mounted to exterior knee-links 26 and interior knee-links 34, themselves pivotally mounted to knee-links 28 and 30 resulting in vertical actuation of spikes 36 upon horizontal translation of shifter frame 20 as transmitted to toe-shifter frame 52, where sub frame 20 e is pivotally mounted onto shaft 32 by hooked tangs 20 f interleaved between and one either side of toe shifter links 54.

In a preferred embodiment, toe shifter frame 52 and corresponding toe mounting plate 18 are laterally offset relative to shifter frame 20 and corresponding mounting plate 14 so as to fit within the asymmetric plan form of a conventional shoe sole, that is, so as to fit within the available area in a toe cap section of the sole forward of the ball portion corresponding to the ball of the foot of the user. In one preferred embodiment which is not intended to be limiting, this arrangement allows for the mounting of two laterally adjacent spike actuating mechanisms on toe mounting plate 18, for substantially equally spaced apart spike actuating mechanisms on ball portion 14 b, and for substantially equally spaced apart spike actuating mechanisms on heel portion 14 a. The spacing apart of the spike actuating mechanisms on the heel and ball portions 14 a and 14 b of mounting plate 14 provide a substantially centrally aligned longitudinally extending corridor between the left and right spike actuating mechanisms on the heel and ball portions of the mounting plate thereby providing room for the shifter frame guides 56 and the push button actuator 48. Shifter guides 56 may include bolts or screws having heads 56 a which overlap on to lands 20 g so as to hold the shifter frame 20 vertically downwards onto mounting plate 14, lands 20 g defining slots 20 h along which the bolts or screws and corresponding heads 56 a slide. The ends of slots 20 h provide stops governing the extent of the longitudinal translation of shifter frame 20 relative to mounting plate 14. The bolts or screws threadably mount down into correspondingly threaded nuts 58 or the like mounted on mounting plate 14 beneath slots 20 h.

Push button actuating device 48 is modeled in its function on that of a push button switch sold by C & K Components under model number PN42LENA02QE and distributed by NEP Electronics Inc. of Wooddale, Ill., USA. Other push-button cyclically actuating positions would work as would be known to one skilled in the art. Push button actuating device 48 includes a leaf spring 60, mounted by a fastener 60 a to the top side of shifter frame 20. Leaf spring 60 has a center opening so that the leaf spring fits over pin holder 62 biasing free end 62 a downwardly. The opposite end of pin holder 62, swivel-mounted end 62 b, is pivotally mounted to shifter frame 20 by means of pin 62 c so as to allow free end 62 a to swivel laterally relative to shifter frame 20 and mounting plate 14 and also to allow free end 62 a to deflect a small amount vertically. Pin 62 d is mounted under free end 62 a so as to depend vertically downwards therefrom. The lower most free end of pin 62 d is free to move within a wide aperture 20 i in sub frame 20 c so that shifter frame 20 does not interfere with the lateral motion of pin 62 d as it travels within channel guides 64 formed in or mounted on waisted portion 14 c of mounting plate 14.

Pin 62 d is resiliently biased in direction J by spring 42 acting on rod 40 and thereby acting on shifter frame 20 to resiliently urge shifter frame 20 in direction A′. Because pin 62 d is mounted onto shifter frame 20 by means of pins 62 c and pin holder 62, urging of shifter frame 20 in direction A′ thereby also urges pin 62 d in direction J. Within channel guides 64, an encircling variable-depth channel 64 a encircles a rigid island 64 b. Island 64 b defines a concave cusp 64 c. When pin 62 d is positioned against cusp 64 c, and in particular against the vertex 64 d of the cusp surface of island 64 b, spring 42 is compressed and shifter frame 20 is translated into its forward-most position corresponding to when spikes 36 are fully extended. When button 38 is then depressed in direction F, thereby driving rod 40 forwardly relative to mounting plate 14, shifter frame 20 is advanced slightly further forwardly thereby pulling pin 62 d along with it in a direction opposite to direction J. This forces pin 62 d in direction K from its position resting against the vertex 64 d while the base of pin 62 d rests on step 64 e. The trajectory of travel of pin 62 d is governed by the walls of channel 64 a on step 64 e. Once pin 62 d has travelled the length of step 64 e in direction K, pin 62 d drops down from step 64 e onto inclined channel floor 64 f under the resilient urging of leaf spring 60 acting downwardly on free end 62 a of pin holder 62.

Thus once button 38 is released so as to allow translation of rod 40 in direction G as spring 42 expands, shifter frame 20 translates in direction A′, that is, in a reversed direction to direction A, thereby translating pin 62 d in direction J so that the base of pin 62 d follows along the inclined floor 64 f of channel 64 a. As shifter frame 20 thus translates rearwardly relative to mounting plate 14, pin 62 d follows in the trajectory defined by the walls of channel 64 a to thereby follow around island 64 b to a position rearmost in channel 64 a where further rearward translation in direction J of pin 62 d is halted by pin 62 d encountering the rearward most curvature position 64 g of channel 64 a. At this point pin 62 d cannot translate in direction J any further and thus rearward translation of shifter frame 20 is halted. This rearward-most position coincides with the rearwardly shifted position of shifter frame 20, that is, coinciding with the fully retracted position of spikes 36.

Upon the next pushing of button 38 in direction F, rod 40 and shifter frame 20 are again translated forwardly and pin 62 d advances the balance of the path around channel 64 a and in particular along the balance of the inclined floor 64 f in direction L whereupon it rounds the forward turn in direction M thereby dropping down from the raised surface of floor 64 f down onto step 64 h. From there pin 62 d returns to its position against vertex 64 d, again biased in that direction by the operation of spring 42.

Thus as may be seen, because of the lateral width occupied by channel guides 64, where the channels must be sufficiently sized to accept pin 62 d, and where pin 62 d must be sufficiently sized so as to be robust to allow longevity of the push button switch operation, it is advantageous to mount channel guides 64 or form channel guides 64 where there is available space on mounting plate 14. Because of the space occupied by the spike actuating mechanisms and spike guides 16, and keeping in mind that it is advantageous in most applications to which sole 10 will be put to maximize the number of spikes 36, the central corridor on heel portion 14 a may be relatively narrow especially for smaller sized soles 10, thus the relatively open space on waisted portion 14 c provides the available room on which to mount or form channel guides 64. Because the central portion of shifter frame 20, that is, sub frame 20 c, transfers the loads in compression and tension as the case may be along two parallel laterally spaced apart rigid stringers 20 j on opposite sides aperture 20 i and pin holder 62, the amount by which stringers 20 j are spaced apart governs the available space within which pin 62 d may be translated laterally when translating in channel 64 a.

The waisted portion 14 c of mounting plate 14 also provides for accommodating the arch of a typical piece of footwear which often dictates the shape of the concavity formed under the arch in the planform of sole 10. In alternative embodiments, if desired, mounting plate 14 may be formed with a slight rocker shape, that is, a slight upward curvature to provide a slightly rockered rigid base under which the resilient portion of sole 10 would be mounted. This may be employed in certain applications of sole 10 where a slightly rockered rigid shape for mounting plate 14 a is desirable rather than being planar shape. Thus a slight curvature might be introduced for example along the waisted portion 14 c while maintaining the heel and ball portions 14 a and 14 b respectively planer. In order to accommodate the translation of shifter frame 20 in such embodiments, sub frame 20 c may be provided with one or more pivotable joints for example formed in stringers 20 j either by the use of pins or by the use of pinned links such as links 54 for example. Thus because shifter frame 20 only has to translate a relatively short distance forwardly and rearwardly relative to mounting plate 14, and because the forward and rearward portions of shifter fame 20 are held by guides 56 flush down against the corresponding portions of mounting plate 14 while still allowing for the relative translation of shifter frame 20 flush over mounting plate 14, such a rocker shape in mounting plate 14, which may be rigid or in alternative embodiments slightly flexible, may be accommodated in alternative embodiments.

Although the structural form described herein of shifter frame 20 is not intended to be limiting, it has been found advantageous to provide the rigid U-shaped collars extending laterally from the longitudinal; back-bone of frame 20 and laterally from toe-shifter frame 52 so that for each spike guide 16 and the related spike actuating linkages on either side of each spike guide 16, a U-shape collar provides for simultaneous actuation of the knee-lever linkages on either side of each spike guide 16. In this fashion, the likelihood of jamming of the linkages is reduced as compared for example to actuating a linkage on only a single side of a spike guide 16. Again, using the U-shaped collar structures lends to the rugged longevity of the shifter frames and spike actuating mechanism, and provides for positive mechanical driving of each spike so as to extend each spike when desired and so as to retract each spike when desired without relying on a small light-weight resilient mechanism such as small springs mounted underneath the user's foot, so that in the present design a single very rugged spring 42 governs the force with which spikes 36 are retracted, the driving force provided by the user against button 38 providing the force to directly and mechanically extend spikes 36.

As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims. 

1. An apparatus for selectively extending and retracting spikes from the sole of a footwear article, the sole having a heel section, a center under-the-arch of the foot section, a ball-of-the-foot section, and a toe section extending consecutively in a longitudinal direction along the sole, and a plurality of spike apertures through the heel, ball and toe sections, the apparatus comprising: a plurality of spike actuating assemblies, each spike actuating assembly of said plurality of spike actuating assemblies having a spike locatable within a corresponding one of the spike apertures; a first plate having heel, center and ball portions sized to extend over so as to cover respectively the heel, center and ball sections of the sole when said first plate is mounted on the sole, an elongate first slider frame translatable mounted flush on said first plate substantially parallel to the longitudinal direction of the sole and having heel, center and ball sub-frames covering respectively said heel, center and ball portions of said first plate and being moveable between first and second positions, said first slider frame operable to actuate said plurality of spike actuating assemblies to thereby extend said spikes from said plurality of spike actuating assemblies at said first position and to retract said spikes at said second position; a cyclically alternating positioner mounted on said first plate for moving said first slider frame between said first and second positions, said positioner having only a single actuating button adjacent said heel portion, wherein depressing said actuating button a first time causes said positioner to move said first slider frame to said first position and wherein depressing said actuating button a second time causes said positioner to move said first slider frame to said second position, a second plate adjacent a front end of said ball portion of said first plate so as to cover the toe section of the sole when said first and second plates are mounted on the sole, a second slider frame slidably mounted flush on said second plate, said second slider frame pivotally mounted to a front end of said ball sub-frame of said first slider frame, at least one of said spike actuating assemblies mounted on said second plate, wherein when said first slider frame is moved between said first and second positions, said second slider frame is correspondingly simultaneously moved relative to said second plate and correspondingly actuates said spike actuating assembly on said second plate to simultaneously extend and retract a corresponding said spike therefrom.
 2. The apparatus of claim 2 wherein said each spike actuating assembly further comprises a rigid housing mounted to said first plate and slidably encasing a corresponding said spike, a knee-lever linkage pivotally mounted at a first end thereof to said rigid housing and at an opposite second end to said first slider frame, wherein said knee-lever linkage includes at least an upper link and a lower link pivotally mounted to one another at a mid-pivot between said first and second ends of said knee-lever linkage, and wherein said mid-pivot is connected to said corresponding spike, and wherein when said first slider frame is in said first position so as to extend said corresponding spike said upper and lower links are substantially linearly aligned and collectively upwardly inclined so as to transfer a substantial vector component of an upward force acting on said corresponding spike to said rigid housing via said mid-pivot and the linearity of said substantially linearly aligned upper and lower links.
 3. The apparatus of claim 1 wherein said center portion of said first plate is waisted when viewed in planform relative to a width of said heel and ball portions, and wherein said center sub-frame of said first slider frame is correspondingly waisted so as to substantially conform in width when overlaid onto said center portion.
 4. The apparatus of claim 3 wherein said positioner includes a cyclical actuator mounted both on said center portion and said center sub-frame so as to cooperate therebetween to drive said first slider frame between said first and second positions relative to said first plate, and wherein a drive member extends between said button and said cyclical actuator.
 5. The apparatus of claims 1-4 wherein said plurality of spike actuating assemblies are mounted on said first plate in spaced apart array so as to provide a longitudinally extending unobstructed center corridor along said first plate extending substantially the entire length of said first plate, and so as to provide longitudinal spacing between said plurality of spike actuating assemblies, and wherein said first slider frame includes a center back-bone frame extending substantially completely along said heel, center and ball sub-frames so as to freely slide along said center corridor of said first plate, and wherein said first slider frame includes, said laterally extending arms from said center back-bone frame extending cooperating with said plurality of spike actuating assemblies so as to actuate said spikes.
 6. The apparatus of claim 5 wherein said laterally extending arms further include longitudinally extending arms at the distal ends of said laterally extending arms so as to define substantially U-shaped brackets around said each spike actuating assembly, wherein said U-shaped brackets drive said each spike actuating assembly simultaneously from opposite sides thereof.
 7. The apparatus of claim 6 wherein said first plate further comprises guide members cooperating with said first slider frame to constrain sliding translation of said first slider frame between said first and second positions, and to constrain said translation to flush translation substantially flush along said first plate.
 8. The apparatus of claim 7 wherein said flush translation is without vertical translation of said first slider frame relative to said first plate.
 9. The apparatus of claim 5 wherein said actuating button comprises a plunger button acting against a return biasing spring.
 10. The apparatus of claim 9 wherein said plunger button is cantilevered from a heel portion of said sole in a substantially horizontal plane.
 11. The apparatus of claim 5 wherein a portion of said sole covers said actuating button.
 12. The apparatus of claim 5 wherein said actuating button is contained within said sole.
 13. The apparatus of claim 5 wherein said positioner is cyclically actuated by single consecutive pushes of said button applied to rear of the sole against a return biasing force of a single resilient biasing spring.
 14. The apparatus of claim 14 wherein said spring acts against and between said first plate and said button.
 15. The apparatus of claim 14 wherein said spring is a helically coiled spring.
 16. The apparatus of claim 15 further comprising a rod extending from said button along said heel portion to said center portion of said first plate, and wherein said rod is journalled through said helically coiled spring.
 17. The apparatus of claim 16 wherein said rod is substantially parallel to said first plate and substantially longitudinally aligned.
 18. The apparatus of claim 2 wherein a third link in said knee-lever linkage is pivotally connected between said mid-pivot and an upper end of said corresponding spike.
 19. The apparatus of claim 18 wherein said upper link is mounted to said housing at an upper end of said housing, and wherein said lower link is mounted to said first slider frame.
 20. The apparatus of claim 19 wherein said housing defines a substantially vertical silo for said corresponding spike to slide vertically therein as said mid-pivot is lowered or elevated upon translation of said first slider frame between said first and second positions respectively. 